Heat exchanger conduit



April 21, 1970 P. MUELLER I 3,507,324

HEAT EXCHANGER CONDUIT Filed May 9, 1968 44 lA/VEA/TQI? PAUL MUELLER United States Patent O 3,507,324 HEAT EXCHANGER CONDUIT Paul Mueller, Springfield, Mo., assignor to Paul Mueller Company, Springfield, Mo., a corporation of Missouri Filed May 9, 1368, Ser. No. 727,764 Int. Cl. F28b 9/26 US. Cl. 165-164 8 Claims ABSTRACT OF THE DISCLOSURE A heat exchanger conduit having substantially concentric partially flattened conveying tubes for conveying fluids, such as fluid food products, isolated from spaces for conveying heat exchanger media. Oppositely offset eccentric inlet and outlet connector sleeves for the entering and leaving fluid to maintain substantially constant fluid velocity and to permit inspection of the interiors of the tubes.

BRIEF DESCRIPTION OF THE INVENTION In this heat exchanger conduit, a plurality of fluid conveying tubes are arranged in a concentric array. The central tube is preferably circular in cross-section and is surrounded by radially spaced, partially cylindrical flattened, laterally curved tubes. The laterally curved side walls of the radially spaced tubes are substantially parallel to one another. The ends of adjacent tubes are welded closed to isolate the spaces between the tubes from the areas within the tubes. A jacket surrounds and is spaced from the outer tubes. The ends of the jacket are welded to the outer surfaces of the outer tubes. All weldings provide complete isolation of the spaces from the interior areas of the tubes, so that heat exchanger medium flowing through the spaces does not come in direct contact with the fluid flowing through the tubes.

Inlet and outlet connector sleeves deliver and receive fluid from the tubes. The connector sleeves are oppositely offset, with tapering side walls. The inlet and outlet sleeves permit inspection of the entire interior of the conduit, while the tapered side walls permit the areas of the ends of the sleeves to be substantially the same as the combined areas of the tubes to maintain constant velocity of the fluid. This constant fluid velocity is especially'important for the most effective cleaning of the fluid passages.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a fragmentary to plan view of the heat exchanger conduit.

FIGURE 2 is a fragmentary side elevation of the heat exchanger conduit.

FIGURE 3 is an enlarged end view of the heat exchanger conduit as viewed from the right side of FIG- URE 2.

FIGURE 4 is an enlarged view in section taken along the line 4-4 of FIGURE 2.

FIGURE 5 is an enlarged view in section taken along the line 5-5 of FIGURE 2.

FIGURE 6 is an enlarged view in section taken along the line 66 of FIGURE 2.

FIGURE 7 is an enlarged view in section taken along the line 77 of FIGURE 2.

FIGURE 8 is an isometric view of a spacer plate.

FIGURE 9 is an isometric view of a spacer weldment.

DETAILED DESCRIPTION OF THE INVENTION The heat exchanger conduit 20 illustrated is generally elongated and cylindrical. However, other shapes are contemplated such as elbows, returns, and the like.

As shown in FIGURES 4, 5, 6 and 7, the passages for conveying fluid which is to be heated or cooled comprise 3,507,324 Patented Apr. 21, 1970 a plurality of tubes 21, 22, 23, 24 and 25, arranged in a substantially concentric array. The central tube 21 is of circular cross-section. A plurality of spacer plates 26 have outer and inner edges 27 and 28, as shown in FIG- URE 8. The inner edges 28 of these spacer plates are welded to the central tube 21, with the spacer plates 26 oriented to extend upwardly and downwardly from the central tube 21. As indicated in FIGURES 4 and 5, these spacer plates 26 are spaced apart longitudinally of the central tube 21.

The tubes 22 and 23, are radially spaced from and generally concentric with the central tube 21. These tubes 22 and 23 are partially flattened to provide transversely arcuate inner and outer walls 30 and 31 extending between narrower walls 32 and 33. The walls 30 and 31 are substantially parallel to one another. The narrower walls 32 and 33 are welded to the spacer plates 26 to position the tubes 22 and 23, and also to space their end walls 32 and 33 apart.

The outer tubes 24 and 25 are also partially flattened to provide inner and outer walls 35 and 36 that are transversely arcuate and substantially parallel to one another. The walls 35 and 36 extend between narrower walls 37 that are welded to the spacer plates 26.

A jacket 40 surrounds the tubes 21, 22, 23, 24 and 25. The jacket has a cylindrical longitudinal wall 41 that is spaced from the outer tubes 24 and 25, and has inwardly curved ends 42 and 43 that are welded to the outer walls 36 of the tubes 24 and 25, with welding extending partially along the ends 37 of the tubes 24 and 25. An inlet port 44 extends through the wall 41 adjacent one end of the conduit, and an outlet port 45 extends through the wall 41 adjacent the other end of the conduit.

There are'a plurality of longitudinal spaces 46, 47, 48, 49, and 51 between the tubes 21, 22, 23, 24 and 25, and between the outer tubes 24 and 25 and the jacket 40. As shown in FIGURES 4 and 5, the ends 53 of the tubes 21, 22, 23, 24 and 25 are deformed so that adjacent tube ends are in contact over as much of their surfaces as possible. These adjacent ends are welded and the welding is done as indicated in FIGURE 3 so that all areas 54 between adjacent tubes are closed. Likewise, the welding between the ends 42 and 43 of the jacket 40 to the tubes 24 and 25 is such as to close all areas between them. Thus, the weldings provide fluid-tight isolation of the interiors of the tubes 21, 22, 23, 24, and 25, from the spaces 46, 47, 48, 49, 50 and 51.

There are a plurality of weldments 56 between adjacent tubes in between the tubes 24 and 25 and the jacket 40 to position and space the tubes and the jacket.

There is an inlet connector sleeve 58 at one end of the conduit 20, and an outlet connector sleeve 59 at the other end of the conduit. The inlet connector sleeve 58 and the outlet connector sleeve 59 are oppositely eccen tric relative to the axis of the conduit 20 with tapered side walls 60 and 61, respectively. Thus, as viewed in FIGURE 2, the axis of the tapered side Wall 60- of the inlet sleeve 58 is in a downward direction, and the axis of the tapered side wall 59 of the outlet sleeve 61 is in an upward direction.

The sleeves 60 and 61 have openings 62 and 63 provided with clamp type ferrules 64 and 65, respectively. These end openings 62 and 63 have cross-sectional areas that are equal or nearly equal to the combined cross-sectional areas of the interiors of the tubes 21, 22, 23, 24, and 25. The clamp type ferrules 64 and 65 permit the conduit 20 to be joined to similar conduits or to return bends or elbows or other connections. The oppositely offset sleeves 58 and 59 permit inspection of the entire interior of the conduit 20, by first viewing from one open end 62, and then viewing from the other open end 63,

as a light is shined into the end opposite the one from which viewing takes place.

In use, the conduit 20 may be joined to other conduits, and to whatever return elbows, and curves are required for a particular installation, with the clamp type ferrules 64 and 65 being used for the connections. Fluid, such as beverage, liquid eggs, soft cheese, slurries, or any other fluid product that is to be heated or cooled enters the inlet opening 62. All the fluid is confined to flow through the tubes 21, 22, 23, 24 and 25, the welding 54 blocking the fluid from flowing into any of the spaces 46, 47, 48, 49, 50 or 51. The fluid exits through the outlet opening 63.

Heat exchanger medium, such as refrigerant, steam, circulating water, glycol, oil, or other heat exchange medium (depending upon whether the fluid is to be heated or cooled) enters through the inlet port 44 and circulates through all communicating spaces 46, 47, 48, 49, 50 and 51, and exits through the outlet port 45. Since the tubes 22, 23, 24, and 25, are partially flattened and curved, maximum surfaces of these tubes are exposed to the heat exchanger medium so that direct heating or cooling of the fluid is substantially increased by this invention.

Cleaning is done by circulating cleaning liquid through the inlet opening 62, the tubes 21, 22, 23, 24 and 25, and the outlet opening 63. Since the sleeves 58 and 59 are tapered to open ends 62 and 63 that are of substantially the same cross-sectional areas as the combined areas of the tubes 21, 22, 23, 24 and 25, the velocity of cleaning liquid entering the inlet connector sleeve 58 is maintained through the tubes 21, 22, 23, 24, and 25. This greatly improves the eifectiveness of the circulating cleaning liquid.

To inspect the conduit 20, it is disconnected by disconnecting the clamp type ferrules 64 and 65 to expose the open ends 62 and 63 for viewing. The entire interiors of the tubes 21, 22, 23, 24, and 25 can be viewed and inspected by alternately viewing from opposite ends of the conduit.

If desired, appropriate thermostats may be connected to the conduit 20. These thermostats may be connected to the jacket 40 adjacent the inlet and outlet ports 44 and 45, or may be set against the tubes 24 and 25 by cutting away and sealing ofi' small areas of the jacket Wall 41 adjacent the inlet and outlet ports 44 and 45.

Various changes and modifications may be made within the purview of this invention as will be readily apparent to those skilled in the art. Such changes and modifications are within the scope and teaching of this invention as defined by the claims appended hereto.

What is claimed is:

1. A heat exchanger conduit presenting a low impedance path for the fluid to be'heated or cooled while at the same time maximizing the degree of heat exchange, the conduit comprising a plurality of partially cylindrical flattened tubes defining a generally concentric array, means supporting the tubes in spaced relation to one another, the tubes being opened at their ends, an outer jacket surrounding the tubes, the outer jacket having a longitudinal wall spaced from the tubes with end portions joined to the outermost tubes, means adjacent the ends of the tubes for blocking the ends of the spaces between the tubes and between the longitudinal wall of the jacket and the outermost tubes, a heat exchanger medium inlet and a heat exchanger medium outlet extending through the longitudinal Wall of the jacket and communicating with the spaces between the tubes and between the longitudinal wall and the outermost tubes, and an inlet connector sleeve and an outlet connector sleeve extending through opposite ends of the jacket and communicating with the interiors of the tubes, whereby heat transfer medium can be circulated through the said spaces past the outer surfaces of the tubes as fluid flows through the tubes.

2. The heat exchanger conduit of claim 1 wherein said partially cylindrical flattened tubes are substantially straight, and the connector sleeves are eccentric to the axis of the conduit in diametrically opposite directions so that the interior surfaces of the tubes can be inspected visually by looking first through one connector sleeve and then the other.

3. The heat exchanger conduit of claim 1 wherein means is provided at the open ends of the inlet and out let sleeves for connecting conduits together.

4. The heat exchanger conduit of claim 1 wherein said interior walls of the partially cylindrical flattened tubes are substantially smooth.

5. The heat exchanger conduit of claim 1 wherein the flattened tubes have opposed wide surfaces between relatively narrower ends and the wide surfaces are transversely arcuate and substantially parallel to one another.

6. The heat exchanger conduit of claim 1 wherein one tube is of circular cross-section and the remaining tubes are partially flattened and arcuate as aforesaid.

7. The heat exchanger conduit of claim 1 wherein the inlet and outlet sleeves are oppositely offset relative to the axis of the conduit, the inlet and outlet sleeves being tapered toward reduced diameter open ends, the total cross-sectional area of each open end of a sleeve being about the same as the combined cross-sectional areas of the interiors of the tubes.

8. The heat exchanger conduit of claim 1 including spacer elements between the tubes for positioning and spacing the tubes relative to one another.

References Cited UNITED STATES PATENTS 1,840,510 1/1932 Kelley l158 2,650,073 8/1953 Holm l40 3,120,868 2/1964 Ballantine 165165 3,333,318 8/1967 Vaeger 165154 X ROBERT A. OLEARY, Primary Examiner T. W. STREULE, Assistant Examiner U.S. Cl. X.R. 165-15 4 

